A polishing head is already known from DE 10 2004 062 319 B3. This polishing head comprises a base body which supports a polishing pad on the one hand and can be fitted to a polishing spindle on the other. In order to perform an automatic tool change, the base body comprises a groove and a rim or a collar each of which extends over the circumference thereof. The groove and the collar are provided in order that the polishing head can be held by a tool change arm of the polishing machine. Between the base body and the tool change arm positioned in the groove or against the collar there is a positive joint acting in the axial direction which ensures that the polishing head can be changed, in particular that it can be fitted to the polishing spindle and removed from the polishing spindle.
The relative position in the circumferential direction between the polishing spindle and the polishing head to be fitted thereto is not known. The polishing head comprises driving lugs engaging with corresponding grooves of the polishing spindle. As a rule, the driving lugs do not yet engage with the grooves of the polishing spindle immediately after the polishing head has been fitted. Said engagement does not take place until the polishing spindle begins to rotate since then there is a relative movement in the circumferential direction between the polishing spindle and the polishing head to be fitted thereto. As soon as the driving lugs and the corresponding grooves are congruent with one another, the polishing head snaps into place under the influence of an axial mounting force exerted by the tool change arm.